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Biomedical subjects

M Durlik

Publications and source records attributed to M Durlik.

At least 55 records · Page 3Linked to original sources
PubMed2000

Kinetics of bone marrow repopulation in lethally irradiated rats after transplantation of vascularized bone marrow in syngeneic hind limb.

Grafting of the recipient with bone marrow cell suspension provides only few stromal cells and no autologous environment for cooperation between hemopoietic and stromal cells. Vascularized bone marrow grafts provide the recipient with bone marrow hemopoietic and stromal cells in their natural spatial relationship. It is expected that such a graft will resume its function soon after transplantation and almost immediately repopulate bone marrow cavities of the irradiated recipient as well as supply the sites of cytopoiesis with the necessary growth factors. The aim of the study was to investigate the process of repopulation of bone marrow cavities and lymphoid organs of irradiated recipient by bone marrow cells from syngeneic hind limb transplant. Lewis rats received total body irradiation of 8 Gy followed by orthotopic transplantation of syngeneic limb or i.v. infusion of equivalent amount of bone marrow cells. In control experiments the hind limb was shielded with lead plate during total body irradiation. Ten days after irradiation and hind limb transplantation the yield of nucleated cells from tibia was reaching values of normal animals. In rats receiving i.v. bone marrow cell infusion it was 40% of control values and in rats repopulated from shielded own hind limb it was 60% of controls. In all groups a higher percentage of early and immediate normoblasts and a reduced pool of juvenile and segmented neutrophils was observed. Thirty days after irradiation and repopulation procedures all parameters were returning to normal levels in each group. The results indicate that bone marrow cell transplantation in hind limb graft is highly effective in lethally irradiated animals in reconstituting bone marrow.

Animals↗
PubMed2000

Usefulness of hybridization and PCR methods in monitoring of CMV infection in renal transplant recipients.

The purpose of this work was to compare hybridization and PCR methods as diagnostic tests in diagnosing and monitoring CMV infection. The investigation was performed in a group of 24 renal transplant recipients treated with ATG. The results we obtained suggest that quantitative variant of hybridization is more useful in diagnosing the infection than PCR, because it enables to monitor the infection. DNA CMV level of about 60 pg/ml or the increasing level in the subsequent samples should be a sign to start antiviral therapy.

Adult↗
PubMed2000

[Evaluation of the usefulness of various PCR method variations and nucleic acid hybridization for CMV infection in immunosuppressed patients].

In diagnosis of CMV infection various laboratory methods are used. The methods based on detection of viral nucleic acids have been introduced routinely in many laboratories. The aim of this study was to compare nucleic acid hybridisation method and various variants of PCR methods with respect to their ability to detect CMV DNA. The studied material comprised 60 blood samples from 19 patients including 13 renal transplant recipients and 6 with acute leukaemia. The samples were subjected to hybridisation (Murex Hybrid Capture System CMV DNA) and PCR carried out in 3 variants: with one pair of primers (single PCR), nested PCR and Digene SHARP System with detection of PCR product using a genetic probe in ELISA system. The sensitivity of the variants ranged from 10(0) particles of viral DNA in nested PCR to 10(2) in single PCR. The producer claimed the sensitivity of the hybridisation test to be 3 x 10(5) and it seems to be sufficient for detection of CMV infection. The obtained results show that sensitivity of hybridisation was comparable to that of single PCR and the possibility of obtaining quantitative results makes it superior, on efficacy of antiviral therapy, especially in monitoring CMV infection in immunossuppressed patients and in following the efficacy of antiviral treatment.

Cytomegalovirus Infections↗
PubMed1999

Fast lymphoid reconstitution after vascularized bone marrow transplantation in lethally irradiated rats.

BACKGROUND: Bone marrow (BM) transplantation for treatment of hematological and solid malignancies is routinely carried out in conjunction with radio- and chemotherapy. Many patients achieve complete remission of the malignant process; however, their lymphohematopoietic recovery remains in most cases incomplete. This is probably due to the functional changes in the recipient BM stromal cells subsequent to myeloablative therapy. Transplantation of BM hematopoietic cells in a spatial relationship with stromal cells would give an insight into the kinetics of hematological repopulation of the recipient. The aim of this study was to investigate the lymphopoietic reconstitution of irradiated rats after vascularized bone marrow transplantation (VBMT) in comparison with i.v. bone marrow cell (BMC) infusion. METHODS: Lewis rats were totally irradiated with 8Gy and repopulated with syngeneic BMC introduced i.v. or in orthotopic hind limb graft. Ten days after irradiation and BMC graft BM, peripheral blood (PB) and mesenteric lymph nodes (MLN) were collected. The yield and the phenotype of cells were analyzed. RESULTS: VBMT brings much higher cell repopulation of BM cavities of lethally irradiated rats than BMC infusion. Orthotopic hind limb graft promotes also rapid lymphocyte replenishment of PB and MLN of lethally irradiated syngeneic recipients. The population rate of BMC, PB lymphocytes, and MLN lymphocytes was higher after VBMT than BMC injection in suspension. The percentage of T and B lymphocytes in PB and MLN on day 10 after VBMT was comparable with control values. Reconstituted PB lymphocytes showed two subsets of CD4+ cells: "bright" and "dull." All CD4+ cells in PB lymphocytes of i.v. BMC infused recipients expressed low level of these molecules ("dull" subset). CONCLUSIONS: The results of our studies indicate that the presence of stromal cells in their close relationship with stem cells is essential for the fast lyphohematopoietic repopulation of irradiated recipients. The population of CD4+dull cells may represent immature cells. These cells were not found in MLN of VBMT rats. All MLN CD4+ cells represented the "bright" subset, what suggests that the process of cell maturation may occur in the lymphoid organs.

Adoptive Transfer↗
PubMed1999

Identification of cytomegalovirus (CMV) infection by different laboratory methods in renal transplant recipients undergoing triple-drug immunosupressive treatment.

Early diagnosis of CMV infection is very important mainly in transplant recipients because CMV infection is a frequent complication after transplantation. In this work we compared different laboratory methods: ELISA (IgG, IgM), Western blot,shell vial, antigenemia assay (pp65), the immunofluorescent method with epithelial cells from urine (IF), DNA in leukocytes by PCR and DNA in leukocytes by hybridization (HCS) to estimate the most proper method for diagnosis of CMV in renal transplant recipients. This preliminary study showed that HCS, PCR and Western blot are sensitive methods for detecting CMV infection. Using HCS in quantitative variant we obtained a very good correlation between DNA load and clinical symptoms.

Adult↗
PubMed1999

Role of adhesion molecules in chronic allograft rejection.

Endothelial adhesion molecules play an important role in T cell recruitment to an allograft site. Therefore, it could be expected that their blocking may be beneficial for allograft survival. In this report, we show that T cells from patients with chronic rejection have an up-regulated ability to adhere to inflamed endothelium in vitro. Furthermore, this enhanced T cell: endothelial interaction could be blocked by anti-VCAM and anti-E-selectin monoclonal antibodies.

Antibodies, Monoclonal↗
PubMed1999

Factors affecting reactivation of Epstein-Barr virus infection after kidney allograft transplantation.

OBJECTIVES: Reactivation of Epstein-Barr virus (EBV) infection in renal transplant recipients may cause significant morbidity and mortality. To evaluate factors associated with activation of EBV replication we followed prospectively a group of 65 recipients of cadaveric kidney for 12 months. METHODS: Sera were collected periodically from these patients and analyzed for the presence of specific anti-EBV antibodies. Control group consisted of renal (n=35) and healthy blood donors (n=35). Enzyme-linked immunoassays based on recombinant EBV proteins were used to detect the following antibody specificities: early antigen (EA) IgA, IgM, and IgG, nuclear antigen (EBNA) IgG. RESULTS: During first year after transplantation, primary infection developed in 4 (6.15%) recipients and reactivation occurred in 18 (27.7%) recipients. Analysis did not show the association of reactivation with type of basic immunosuppressive therapy, prophylactic or therapeutic use of anti-lymphocyte antibodies, as well as acute rejection episodes. There was a borderline association (p=0.068) between the incidence of CMV infection and EBV reactivation. CONCLUSIONS: Our data suggest casual relationship between CMV infection and EBV reactivation.

Adult↗
PubMed1999

DNA from rejecting allografts can be detected in recipient nonlymphoid tissues.

The main source of donor DNA in recipients of allograft are "passenger" cells. They are claimed to be responsible for the posttransplantation microchimerism and prolongation of allograft survival. We have noticed that beside of the cellular microchimerism, donor DNA can be found in the recipient tissues at the time of rejection of allograft. In this study we provide evidence for presence in the recipient of both, DNA in "passenger cells" and free DNA in tissues at terminal stage of rejection. Male BN (RTIn) rat heart or skin were transplanted to female LEW (RTII) rats followed by a vascularized bone marrow in hind-limb transplant. CsA was given in a dose of 17mg/kg b.w. for 30 days, then rats were followed until day 100 unless rejection occurred earlier. LEW blood, spleen, mesenteric node and bone marrow cells were stained with moAb OX27 specific for BN but not LEW. Genomic male DNA was isolated and amplified with SRY oligonucleotide. At day 30 and 100 cellular microchimerism was detected in blood, spleen, nodes and bone marrow cells. Donor DNA was detected in recipient skin, liver and heart extracts, beside of lymphoid organs, at the time of rejection of allograft but not when rats were maintained on CsA. Taken together, donor DNA can be detected in recipient tissues at the time of heart or skin rejection. It seems to be released from cells of rejecting grafts and not from "passenger" cells representing only a minor cellular mass compared with the graft.

Animals↗
PubMed1998

Cyclosporine A blood concentration during pregnancy in renal allograft recipients.

Pregnancy-induced changes increase hazards associated with cyclosporine (CsA) treatment. Blood CsA trough levels (C0) were estimated in 15 pregnant renal allograft recipients treated with prednisolone + CsA + azathioprine using the TDx Abbott fluorescent polarization immunoassay. Despite therapeutical dose levels of CsA administered during pregnancy (3.52-3.67 and 3.59 mg/kg body weight in the first, second, and third trimesters, respectively), C0 significantly decreased (first trimester 130.8 +/- 36.9, second 92.0 +/- 32.7, and third 99.0 +/- 36.9 ng/ml). The mean increase of patient's body weight in mid-pregnancy was 3.0 +/- 2.19 kg and was associated with a significant (P < 0.05) fall in a hematocrit value (from 42 +/- 4.9% prior to pregnancy to 34 +/- 6% at the 20th week). We postulate that C0 concentration does not reflect the true exposure to CsA as no episodes of acute graft rejection were observed during pregnancy.

Adult↗
PubMed1998

Long-term results of treatment of chronic hepatitis B, C and D with interferon-alpha in renal allograft recipients.

The aim of this study was to evaluate the efficacy and safety of interferon-alpha (IFN-alpha) therapy of chronic hepatitis B, C and D (HBV, HCV and HDV, respectively) in renal transplant recipients. A group of 42 patients (30 males, 12 females, mean age 38 years) with documented viraemia and chronic active hepatitis (CAH) were studied, of whom 1 had HBV infection alone, 11 had HCV infection alone, 3 had HBV and HDV infection concomitantly, 12 had HBV and HCV infection concomitantly, and 2 had HBV, HCV and HDV infection concomitantly. Patients received 3 MU IFN-alpha three times weekly for 6 months. After IFN-alpha therapy, 18 patients (43%) achieved normal alanine aminotransferase (ALT) activity and a partial response was observed in 12 (29%) patients. Two patients relapsed (one with HCV and one with HBV + HCV infection) immediately after the cessation of IFN-alpha therapy. Repeated liver biopsy was performed in 16 patients after 6-24 months of therapy and revealed progression to cirrhosis in five patients, remission in two and stable disease in nine. None of the patients cleared HCV RNA, four patients cleared HBeAg (two also HDV), and one both HBV and HCV. Five patients died during IFN-alpha therapy (one as a consequence of liver failure), and four died during the 6 months after therapy (two as a consequence of liver failure). During IFN-alpha therapy renal allograft function remained stable in 31 patients and acute rejection episodes occurred in 7, of whom 5 lost their graft and all had experienced rejection episodes before. In 16 patients normalization of ALT continued during long-term follow-up (median 22 months, range 0-84 months). IFN-alpha seemed to be moderately effective in the treatment of chronic HBV or HCV infections, but cannot be recommended for recipients infected with both HBV and HCV.

Adult↗
PubMed1998

Tolerance induction following allogeneic vascularized bone marrow transplantation--the possible role of microchimerism.

We have noticed that bone marrow transplanted in a vascularized limb graft, providing a continuous supply of donor bone marrow cells (BMC), may prolong the survival time of a skin graft from the same donor. The question arises whether the microchimerism raised plays a role in the prolonged survival of skin allografts. The aim of the study was to follow the development of microchimerism after allogeneic vascularized bone marrow transplantation (VBMTx) concomitantly with the rejection process of transplanted skin. Brown Norway (BN) rats served as donors and Lewis rats as recipients of VBMTx and free skin flap allografts. A hind limb was transplanted, followed by a full-thickness skin graft on the dorsum. Cellular microchimerism was investigated in recipients of VBMTx and skin grafts in blood, spleen, mesenteric lymph node, and bone marrow with the monoclonal antibody OX27 directed against MHC class I polymorphic RT1 on BN cells and quantitatively analyzed in a FACStar. In the VBMTx group, the free skin flap survived 70 days after weaning off cyclosporine A (CsA). An intravenous infusion of BMC in suspension equivalent to that grafted in the hind limb did not prolong skin graft survival after cessation of CsA therapy. Donor-derived cells could be detected in VBMTx recipients as long 70 days after weaning off CsA but not in recipients of i.v. suspension BMC grafting.

Animals↗